An oil dipper is a small container that holds painting oil medium for oil painting.

Oil painting often uses drying oil, volatile oil, and other painting oil mediums to alter the stretch and luster of the actual paint. Just as they have quick access to the paint on their palettes, painters can thus work much more efficiently when they have oil at the ready. Oil dippers are lightweight containers that clip on to the edge of the palette, providing artists with a convenient, portable way of mixing oil with paint, and also have lids that store and preserve painting oil medium when properly sealed (although oil dippers are not recommended for long-term storage). Oil dippers come in many shapes and configurations. Examples include the soroban type, which can tip over to a certain degree and still not spill, and the tube type, which makes cleanup a much easier task. Each of these types is also available in various sizes and sometimes even “double dipper” sets that combine two dippers. Most oil dipper containers are made of metals like brass and aluminum, but there are low-cost plastic dippers on the market, as well.

When filling an oil dipper with painting oil medium, try to fill the container about halfway; putting too much medium in the dipper can cause spills when you tilt your palette to the side. In the oil painting sketching stage, the oil dipper only contains turpentine oil or another type of volatile oil. During actual painting, however, the container holds a mixture of volatile oil and drying oil. As your painting nears completion, the oil dipper should contain a larger proportion of drying oil. To paint using an oil dipper, an artist usually puts the necessary amount of paint on the palette, dips the brush tip into the oil dipper to collect the right amount of painting oil medium, and then adds the medium to the paint to create a mixture. When you perform these steps, avoid adding too much painting oil medium to the paint at once; instead, try to mix the medium in little by little.

Artists have to keep several points in mind when using oil dippers. First, replace the painting oil medium as quickly as possible when it starts to get murky and dirty with paint. If you have leftover painting oil medium, you should either use it up that day or throw it away. You also need to clean out the inside of your oil dipper after you finish using it. Every time you start working, you should have fresh painting oil medium in your dipper. Another important point to note is that mixtures of volatile oil and drying oil change over time, with the various components taking on different mixture proportions. If you need to store leftover painting oil medium for 1–3 days, however, wipe the opening of the container thoroughly with a cloth and make sure the lid is closed tight. To clean paint off the outer surface of the oil dipper, rub the area with a cloth soaked in a small amount of volatile oil or paint remover. Oil dippers are available for purchase at general art supply stores.